So it is positive that security group is also pushing for it, alongside .NET and Core Guidelines for C++.
Now how much politic weight they are able to carry, remains an open question. If WinDev was more sympathetic towards DevDiv probably Longhorn would have actually happened, as proven by Singularity and Midori.
Rust is a completely different story. Sure, Rust's standard library treats OOM is fatal, which is the right thing for almost all application code, but it's not difficult to create Rust libraries that treat OOM as a recoverable error, or that don't allocate at all.
If the Singularity group had invented Rust instead of Sing# things might have turned out differently.
Multiple OSes have been written in GC enabled system languages.
Having a GC doesn't mean all memory is required to be GC allocated on the heap, usually the same mechanisms of a language like C++ are also available, e.g. Modula-3, System C#, D and so forth.
Joe Duffy clearly states in one of his Midori talks that WinDev did not believe in Midori, even with it running in front of them.
Longhorn would have happened if it were feasible and AFAIK it was one of the reasons for why Windows Vista took so long.
Now after Midori, and the way things turned out for UWP, we are coming back full circle with .NET 5, XAML Islands and WinUI.